DC modulation noise in clustered particulate media

Mallinson’s theory of recording media noise is extended to ensembles where the particles have an easy axis distribution or are clustered. The effect of clusters is that there is a critical value of packing fraction at which noise in the demagnetised state switches to a minimum. Comparison is made with measurements of DC modulation noise in double layer MP tape

Photo Acoustic Study Of Plants Exposed To Varying Light Intensity Growth Conditions: Spectral And Morphological Changes

In this paper we describe results of photo acoustic (PA) measurements carried out on various plants exposed to varying light intensity conditions. Depending on the species and light intensity conditions, the PA absorption spectra show differences in peaks associated with pigments and the cuticle. These differences are related to the spatial distribution of the pigments that differs from plant to plant. We have also performed systematic study of oxygen evolution at different wavelengths. The obtained oxygen spectra are equivalent to the action spectra usually acquired by determining the CO2 uptake and energy storage. The intensities of oxygen spectra exhibit differences depending on distinct morphology of plant. © EDP Sciences.125745748Marquezini, M.V., Cella, N., Mansanares, A.M., Vargas, H., Miranda, L.C.M., (1991) Meas. Sci. Technol., 2, p. 396Barja, P.R., Mansanares, A.M., (1998) Instrum. Sci. Technol., 26, p. 209Barja, P.R., Mansanares, A.M., Da Silva, E.C., Magalhães, A.C.N., Alves, P.L.C.A., (2001) Photosynthetica, 39, p. 489Salisbury, F.B., Ross, C.W., (1992) Plant Physiology, , Wadsworth Publishing Company, CaliforniaClark, J.B., Lister, G.R., (1975) Plant Physiol., 55, p. 401Carpentier, R., Larue, B., Leblanc, R.M., (1983) J. Physique Colloque C6, 44 (10 SUPL), pp. 355-360Veeranjaneyulu, K., Charland, M., Charlebois, D., Leblanc, R.M., (1991) Photosynth. Res., 30, p. 13

Qualidade de carcaça de novilhos terminados com dietas contendo levedura, monensina e associação de ambos aditivos

To evaluate the effects of the supplementation of feed additives on carcass quality in beef cattle, 72 Nellore steers (339.5kg, 20-month old) were feedlot finished and fed for 91 days one of the following diets: 1) control with no additives; or added of 2) live yeast culture; 3) monensin; or 4) the association of both additives. After slaughter, renal, pelvic, and inguinal fat and hot carcass weights were recorded and carcass was split into muscle, bone, and trimmable fat. Carcass Longissimus muscle area and subcutaneous fat thickness at the 12th rib were measured and steaks of Longisimus muscle were taken to determine meat color, shear force, drip, and cooking losses. Yeast increased carcass dressing percentage but there were no effects on hot carcass weight, Longissimus area, subcutaneous fat thickness, percentage and weight of retail cut yield and trimmings. Feed additives had no effect on carcass pH, meat color, fat content, shear force, and drip losses. Supplementation of yeast, monensin or the association of both additives had no important effects on carcass traits and on meat quality of feedlot finished steers.Avaliaram-se os efeitos da suplementação de aditivos alimentares sobre a qualidade de carcaça em bovinos de corte. Usaram-se 72 novilhos Nelore com média de peso de 339,5kg e 20 meses de idade, terminados em confinamento e alimentados por 91 dias com uma das quatro dietas: 1) dieta controle sem aditivos, ou com a adição de 2) leveduras vivas, 3) monensina ou 4) associação entre ambos aditivos. Após o abate, os pesos da gordura renal, pélvica e inguinal e da carcaça foram medidos e a carcaça dividida em músculos, ossos e aparas. Foram mensurados a área de olho de lombo e a espessura de gordura subcutânea sobre o músculo Longissimus na região da 12ª costela e foram obtidos bifes para a determinação da cor, força de cisalhamento e perdas por cocção e cozimento da carne. A levedura aumentou o rendimento de carcaça, mas não houve efeito dos tratamentos sobre o peso de carcaça, porção comestível e aparas. Os aditivos não influenciaram o pH da carcaça, a cor, a gordura intramuscular, a força de cisalhamento e as perdas por exsudação da carne. A suplementação, com levedura e com monensina em associação ou separadamente, não teve efeito importante sobre a qualidade da carcaça em novilhos terminados em confinamento.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Optimized Profile Retrievals of Aerosol Microphysical Properties from Simulated Spaceborne Multiwavelength Lidar

This work is an expanded study of one previously published on retrievals of aerosol microphysical properties from space-borne multiwavelength lidar measurements. The earlier studies and this one were done in the framework of the NASA Aerosol-Clouds-Ecosystems (now the Aerosol Clouds Convection and Precipitation) NASA mission. The focus here is on the capabilities of a simulated spaceborne multiwavelength lidar system for retrieving aerosol complex refractive index (m = mr + imi) and spectral single scattering albedo (SSA(λ)), although other bulk parameters such as effective (reff) radius and particle volume (V) and surface (S) concentrations are also studied. The novelty presented here is the use of recently published, case-dependent optimized-constraints on the microphysical retrievals using three backscattering coefficients (β) at 355, 532 and 1064 nm and two extinction coefficients (α) at 355 and 532 nm, typically known as the stand-alone 3β + 2α lidar inversion. Case-dependent optimized-constraints (CDOC) limit the ranges of refractive index, both real (mr) and imaginary (mi) parts, and of radii that are permitted in the retrievals. Such constraints are selected directly from the 3β + 2α measurements through an analysis of the relationship between spectral dependence of aerosol extinction-to-backscatter ratios (LR) and the Ångström exponent of extinction. The analyses presented here for different sets of size distributions and refractive indices reveal that the direct determination of CDOC are only feasible for cases where the uncertainties in the input optical data are less than 15%. For the same simulated spaceborne system and yield than in Whiteman et al., (2018), we demonstrated that the use of CDOC as essential for the retrievals of refractive index and also largely improved retrieval of bulk parameters. A discussion of the global representativeness of CDOC is presented using simulated lidar data from a 24 h satellite track using GEOS model output to initialize the lidar simulator. We found that CDOC are representative of many aerosol mixtures in spite of some outliers (e.g. highly hydrated particles) associated with the assumptions of bimodal size distributions and of the same refractive index for fine and coarse modes. Moreover, sensitivity tests performed using synthetic data reveal that retrievals of imaginary refractive index (mi) and SSA are extremely sensitive to β(355).Marie Skłodowska-Curie Research Innovation and Staff Exchange(RISE) GRASP-ACE (grant agreement No 778349

Characterization Of Human Skin Through Photoacoustic Spectroscopy

The photoacoustic technique is based on the absorption of modulated light by a sample and subsequent heat generation. This generates thermal waves that propagate in the surrounding media According to the Rosencwaig-Gersho Model, such waves produce the pressure oscillation detected as the photoacoustic signal. This technique allows the spectroscopic characterization of multilayer systems: as the thermal diffusion length varies with the modulation frequency of the absorbed light, the depth profile of a sample can be studied by the analysis of the photoacoustic signal at different modulation frequencies. In this work, photoacoustic spectroscopy was used to characterize different human skin samples. Measurements were performed at 70Hz and 17Hz, using a 1000W Xe arc lamp as the light source, for wavelengths between 240nm and 700nm. Skin samples were about 0,5cm diameter. It was possible to obtain the photoacoustic absorption spectra of the stratum corneum and of a deeper layer of epidermis; when the lower modulation frequency is utilized, photoacoustic spectroscopy characterizes the absorption of the whole epidermis, because in this case the thermal diffusion length is thicker than that of the stratum corneum. Photoacoustic spectroscopy was also employed to monitor the drying kinetics of the skin. This was done by analyzing the time evolution of the photoacoustic spectra of skin samples. Pre-treatment of the samples included different periods in a drying chamber. Measurements show that the photoacoustic spectra changes according to the humidity of the skin. Future work includes detailed monitoring of skin hydration.5325136142Morganti, P., Ruocco, E., Wolf, R., Ruocco, V., Percutaneous absorption and delivery systems (2001) Clinics in Dermatology, 19, pp. 489-501Junqueira, L.C., Carneiro, J., (1995) Histologia Básica, 8a Ed., pp. 301-303Bernengo, J.C., Gasquez, C., Falson-Rieg, F., Photoacoustics as a tool for cutaneous permeation studies (1998) High Temperatures-High Pressures, 30, pp. 619-624Gutiérrez-Juárez, G., Vargas-Luna, M., Córdova, T., Varela, J.B., Bernal-Alvarado, J.J., Sosa, M., In vivo measurement of the human skin absorption of toppically applied substances by photoacoustic technique (2002) Physiological Measurement, 23, pp. 1-12Puccetti, G., Lahjomri, F., Leblanc, R.M., Pulsed photoacoustic spectroscopy applied to the diffusion of sunscreen chromophores in human skin: The weakly absorbent regime (1997) Journal of Photochemistry and Photobiology B: Biology, 39, pp. 110-120Vinha, C.A., Haas, U., Qualitative and semiquantitative analysis of dried fruits and seasoning products of paprika using photoacoustic spectroscopy (1997) Journal of Agricultural and Food Chemistry, 45 (4), p. 127

Multi-score Learning for Affect Recognition: the Case of Body Postures

An important challenge in building automatic affective state recognition systems is establishing the ground truth. When the groundtruth is not available, observers are often used to label training and testing sets. Unfortunately, inter-rater reliability between observers tends to vary from fair to moderate when dealing with naturalistic expressions. Nevertheless, the most common approach used is to label each expression with the most frequent label assigned by the observers to that expression. In this paper, we propose a general pattern recognition framework that takes into account the variability between observers for automatic affect recognition. This leads to what we term a multi-score learning problem in which a single expression is associated with multiple values representing the scores of each available emotion label. We also propose several performance measurements and pattern recognition methods for this framework, and report the experimental results obtained when testing and comparing these methods on two affective posture datasets

Sunscreen Effects In Skin Analyzed By Photoacoustic Spectroscopy

In the photoacoustic technique, the signal is proportional to the heat produced in a sample as a consequence of modulated light absorption. This technique allows the spectroscopic characterization of multilayer systems: as the thermal diffusion length varies with the light modulation frequency, one can obtain the depth profile of the sample by analyzing the frequency-dependence of the signal. As the photoacoustic signal depends on thermal and optical properties of the sample, structural changes in the system under analysis account for signal variations in time. In this work, photoacoustic spectroscopy was used to characterize samples of sunscreen and the system formed by sunscreen plus skin. Measurements used a 1000W Xe arc lamp as light source, for wavelengths between 240nm and 400nm. This range corresponds to most of the UV radiation that reaches Earth. Skin samples were disks of about 0,5cm diameter. The absorption spectrum of sunscreen was obtained. Finally, photoacoustics was employed to monitor the absorption kinetics of the sunscreen applied to skin samples. This was done by applying sunscreen in a skin sample and recording the photoacoustic spectra in regular time intervals, up to 90 minutes after application. According to measurements, light absorption by the sunscreen plus skin system stabilizes between 25 and 45 minutes after sunscreen application. Results show that this technique can be utilized to monitor drug delivery and farmacokinetics in skin samples.5325143149Barja, P.R., (1996) Estudo da Indução Fotossintética Através da Técnica Fotoacústica: Efeitos de Saturação e Fotoinibição, , (master thesis), IFGW, UNICAMPRosencwaig, A., (1980) Photoacoustics and Photoacoustic Spectroscopy, pp. 219-231. , New York, John Wiley & SonsPucceti, G., Leblanc, R.M., A comparative study on chromophore diffusion inside porous filters by pulsed photoacoustic spectroscopy (1996) Journal of Membrane Science, 119, pp. 213-228Gutiérrez-Juárez, G., Vargas-Luna, M., Córdova, T., In vivo measurement of the human skin absorption of topically applied substances by photoacoustic technique (2002) Physiological Measurement, 23, pp. 1-12Bernengo, J.C., Photoacoustics as a tool for cutaneous permeation studies (1998) High Temperatures-high Pressures, 30, pp. 619-624Azevedo, J.S., UVA/UVB sunscreen determination by second-order derivative ultraviolet spectrophotometry (1999) II Farmaco, 54, pp. 573-578Rettberg, P., Horneck, G., Biologically weighted measurement of UV radiation in space on Earth with the biofilm technique (2000) Advanced Space Research, 26, pp. 2005-2014Van Der Leun, J.C., UV radiation from sunlight: Summary, conclusions and recommendations (1996) Journal of Photochemistry and Photobiology B: Biology, 35, pp. 237-2441Wolf, R., Sunscreens (2001) Clinics in Dermatology, 19, pp. 452-45

Photoacoustics As A Tool For The Diagnosis Of Radicular Stress: Measurements In Eucalyptus Seedlings

The application of the open photoacoustic cell (OPC) to investigate the behavior of eucalyptus leaves by the availability of soil and nutrients for the seedlings was discussed. Fluorescence and photosynthetic rate were evaluated in vivo and in situ, the latter one using the open photoacoustic technique. It was shown that the photosynthetic behavior of seedings are affected by radicular stress, with the soil volume of the pot becoming insufficient for the roots, causing a nutritional deficiency in plants.741 II709711Fork, D.C., Herbert, S.K., (1993) Photochem. Photobiol., 57, p. 207Malkin, S., Canaani, O., (1994) Annu. Rev. Plant Physiol. Plant Mol. Biol., 45, p. 493Malkin, S., Puchenkov, O., (1997) Progress in Photothermal and Photoacoustic Science, Life and Earth Sciences, 3, pp. 17-56. , edited by A. Mandelis and P. Hess (SPIE, Bellingham, WA)Herbert, S.K., Han, T., Vogelmann, T.C., (2000) Photosynth. Res., 66, p. 13Malkin, S., (1987) Planta, 171, p. 65Perondi, L.F., Miranda, L.C.M., (1987) J. Appl. Phys., 62, p. 2955Marquezini, M.V., Cella, N., Mansanares, A.M., Vargas, H., Miranda, L.C.M., (1991) Meas. Sci. Technol., 2, p. 396Pereira, A.C., Neto, G.D.O., Vargas, H., Cella, N., Miranda, L.C.M., (1994) Rev. Sci. Instrum., 65, p. 1512Silva, W.J., Prioli, L.M., Miranda, L.C.M., Cella, N., Vargas, H., Mansanares, A.M., (1995) Plant Sci., 104, p. 177Barja, P.R., Mansanares, A.M., (1998) Instrum. Sci. Technol., 26, p. 209Blake, S.T., (1977) Austrobaileya, 1, p. 7Pryor, L.D., Williams, E.R., Gunn, B.V., (1995) Aust. Syst. Bot., 8, p. 7Inoue, M.T., Oda, S., (1998) Proceedings of the International Symposium on Forest Tree Physiology, p. 69. , NancyBarja, P.R., Mansanares, A.M., Da Silva, E.C., (2001) Acoust. Phys., 47, p. 1

Quinze anos de monitorização das comunidades biológicas do estuário do Tejo no âmbito da construção e funcionamento das ETARs do Portinho da Costa e da Mutela (Concelho de Almada): Experiência adquirida e ensinamentos para futuros casos semelhantes.

Desde 2001 que a Câmara Municipal de Almada tem vindo a promover, em colaboração com o MARE, a monitorização ambiental das regiões estuarinas sob influência das ETARs do Portinho da Costa e da Mutela, que vieram substituir efluentes não tratados emitidos sensivelmente nas mesmas regiões. O objetivo deste programa de monitorização consiste em avaliar as principais alterações ocorridas (na maioria dos casos positivas) nos ecossistemas estuarinos dos vários locais, após a entrada em funcionamento de ambas as infraestruturas. Estes 15 anos de estudos das comunidades bentónicas e de peixes locais têm permitido identificar variações nos padrões espácio-temporais destes compartimentos biológicos e identificar quais dessas evoluções podem ser presumivelmente relacionáveis com o funcionamento das infraestruturas e quais derivam provavelmente de flutuações naturais. Nesta comunicação são enunciados os pressupostos do estudo, descritos os delineamentos experimentais e metodologias de tratamento dos dados adotados, apresentados os principais resultados obtidos e discutidas as grandes dificuldades sentidas para cumprir os objetivos estabelecidos. Este conjunto de elementos será analisado numa perspetiva de como a experiência adquirida pode ser útil, no futuro, para casos semelhantes, sobretudo numa ótica da correta identificação dos verdadeiros efeitos infraestruturais e de despiste da influência de outros fatores concorrentes